There are two important targets on G1. Anglo-Egypt, and the UK battleship.
Other targets are targets of opportunity - Karelia is easy to take, so might as well be taken. Caucasus is sometimes open for a cost-effective capture. In a few games, Germany might be able to crack West Russia early.
But the important targets are targets that Germany should almost always take regardless of how the rest of what other opportunities present themselves. The only exception is if an immediate and real threat to Moscow can be presented. (i.e. not a threat that Russia will just smash on its turn, but something that Russia can’t counter, nor can the rest of the Allies).
Why do I classify Anglo and the battleship as important targets?
1. Anglo. Fighter reinforcement to India, fighter reinforcement to Indian fleet, fighter helps to attack isolated Japanese transports early game, infantry and tank are able to consolidate at another position.
2. Battleship. With a build of 2+ fig, UK becomes an early naval power. Battleships plus transports plus fighters and bombers attack, then retreat. The battleships absorb two free hits, transports are there for a safety factor. On the attack later, Germany has to take care of those two free battleship hits, a real pain. Mid to late game, two battleshop support shots accompanying a lone infantry deplete the German western infantry reserve at no real risk or harm to the Allies, while other UK transports offload to Norway/Karelia/Eastern Europe.